In your 20s you can be more carefree.
"In your 20s it really shouldn't matter that much," Bethenny says. "You can date someone who is figuring out what they're doing—everyone has a lot less responsibility."
But in your 30s you should get more specific—and that's a good thing.
"The type of person you date becomes more important because you may have a child or you're already settled into you career," Bethenny says. "What's good about your 30s—and even more in your 40s—is that you are so specific about the type of person you want to be with so you don't waste any time." Dating a guy who is serious about embracing family and ready to put the boys-weekends in Vegas behind him is paramount.
The advice Bethenny would give her 20-something self: have fun.
While it's normal to feel lonely in your 20s and crave a date around the holidays, don't make yourself feel bad about being single. "The truth of the matter is that it doesn't matter if you have a date on New Year's Eve when you're in your 20s," Bethenny says. "You're supposed to be having fun, meeting all kinds of people, and planting seeds for the future. So I would say have fun. Be capable of being alone. Know that later on you'll have so many responsibilities that are work and children and family obligations. When you're young you get to just get away with it. Just be free."
And for the single 30-somethings, you need to realize you're not old!
"You think 30 sounds like you're getting old and you're supposed to know everything you want to do by the time you're 35, but thinking like that is just a waste of time. You have to beat it into your head that you really are young!"
Always lead an interesting life outside of your relationship, no matter your age.
"Don't be that girl who drops everything for guys—he decides he wants to go out for a guy's night, and then she calls her girlfriends. You need to be interesting and have a life of your own even if you're in a relationship."